Shanghai yufang yixue (Apr 2024)
Antibody levels against varicella-zoster virus in healthy individuals aged 1 to 30 years in Songjiang District of Shanghai in 2022
Abstract
ObjectiveTo determine the antibody levels of varicella-zoster virus (VZV) in healthy individuals aged 1 to 30 years in Songjiang District of Shanghai, and to provide evidence for further development of varicella immunization strategies for healthy population.MethodsSix village committees were selected in Songjiang District through multi-stage stratified random sampling method from July to September 2022. Healthy individuals aged 1 to 30 years old in these villages were recruited and 3‒5 mL of venous blood was collected. Anti-VZV IgG antibody was tested by ELISA. Positive rate of anti-VZV IgG antibody and geometric mean concentration (GMC) were determined.ResultsA total of 315 healthy individuals aged (10.97±8.38) years were included in this study, of which 165 were males aged (11.00±8.52) years and 150 were females aged (10.96±8.25) years. Blood samples were collected and tested for anti-VZV IgG antibody, with the overall positive rate of 55.24% (174/315). The GMC was calculated to be 99.73 mIU·mL-1, with the GMC in those tested positive for anti-VZV IgG antibody of 413.11 mIU·mL-1. The positive rate of anti-VZV IgG antibody and GMCs across age groups ranged between 13.33%‒86.67% and 16.36‒355.14 mIU·mL-1, respectively. The highest GMC was found in the group of 20‒30 years old (355.14 mIU·mL-1), followed by 132.41 mIU·mL-1 in the group of 5‒ years old and 138.12 mIU·mL-1 in the group of 15‒ years old. Moreover, the positive rate was 38.47% in the group with 1-dose varicella vaccine and 63.49% in the group with 2 doses, while the GMC were 53.28 mIU·mL-1 and 130.79 mIU·mL-1 in these two groups, respectively. Multivariable analysis revealed that occupation was a risk factor associated with anti-VZV IgG antibody (OR=2.540). Stratified analysis by varicella immunization history showed that among 2-dose vaccination group, time interval since the last dose was a protective factor (OR=0.315).ConclusionsThe overall positive rate of anti-VZV IgG antibody in healthy population in Songjiang District of Shanghai remains low. The 2-dose varicella vaccination should be strengthened to improve the coverage in susceptible population.
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